objective-c,superclass,objective-c-runtime,swizzling,isa-swizzling
Assume the following class hierarchy. Class A is publicly declared: @interface A : NSObject + (A)createInstance; - (void)a; @end Class _B is a private subclass of A: @interface _B : A - (void)a; - (void)b; @end Assume objects of class A should only be created using the factory method createInstance,...